Welcome to Bimmerfest -- The #1 Online Community for BMW related information! Please enjoy the discussion forums below and share your experiences with the 200,000 current, new and past BMW owners. The forums are broken out by car model and into other special interest sections such as BMW European Delivery and a special forum to voice your questions to the many BMW dealers on the site to assist our members!

E39 (1997 - 2003) The BMW 5-Series (E39 chassis) was introduced in the United States as a 1997 model year car and lasted until the 2004 when the E60 chassis was released. The United States saw several variations including the 525i, 528i, 530i and 540i. -- View the E39 Wiki

About 2 weeks ago replaced (car was running fine prior too)waterpump thermostat and housing, radiator and reserve tank(all parts purchased from pepboys minus reserve tank), bleed system test drove for about 20 minutes at night everything worked great. Next morning checked fluid level before taking off on the freeway(everything looked okay), about 5 minutes into the drive the temperature jumped to about 3/4 pulled car over right away opened vents to release preasure from system, opened radiator cap after system cooled a bit then started car and proceeded to add water back into the reserve tank while bleeder valves were opened, noticed once the water level was to level and the temp was at running temperature the water appeared to rise and fall (about 2 inches)within the reserve tank almost like something was opening and closing internally. Does this sound familiar to anyone out there and if so what was the true cause? faulty new thermastat?

About 2 weeks ago replaced (car was running fine prior too)waterpump thermostat and housing, radiator and reserve tank(all parts purchased from pepboys minus reserve tank), bleed system test drove for about 20 minutes at night everything worked great. Next morning checked fluid level before taking off on the freeway(everything looked okay), about 5 minutes into the drive the temperature jumped to about 3/4 pulled car over right away opened vents to release preasure from system, opened radiator cap after system cooled a bit then started car and proceeded to add water back into the reserve tank while bleeder valves were opened, noticed once the water level was to level and the temp was at running temperature the water appeared to rise and fall (about 2 inches)within the reserve tank almost like something was opening and closing internally. Does this sound familiar to anyone out there and if so what was the true cause? faulty new thermastat?

2001 525i

I think bleeding takes about 3 tries or 2 overheats to do correctly if you're new.

Correct me if I'm wrong, It's been a while since I dealt with cooling issues; if you put the ignition to position 2 (not started) and crank the heater (both the digital thermostat and the heat mixer in between the vents), the system should bleed itself, keep the fill valve open and you'll see the return of coolant to the reservoir.

Cut the ignition on, no further--set the heat as high as it will go and then turn the fan on as high as it will go--leave the engine off--just the ignition on--then fill and bleed the system--you don't have to crank the m54 engine to bleed the system properly--the the aux water pump do the work and you can doing once and go from there--almost forgot--have the front of the car about six inchesd higher than the rear of the car--helps all the air in the system come to the front end and be bleed out.

About 2 weeks ago replaced (car was running fine prior too)waterpump thermostat and housing, radiator and reserve tank(all parts purchased from pepboys minus reserve tank), bleed system test drove for about 20 minutes at night everything worked great. Next morning checked fluid level before taking off on the freeway(everything looked okay), about 5 minutes into the drive the temperature jumped to about 3/4 pulled car over right away opened vents to release preasure from system, opened radiator cap after system cooled a bit then started car and proceeded to add water back into the reserve tank while bleeder valves were opened, noticed once the water level was to level and the temp was at running temperature the water appeared to rise and fall (about 2 inches)within the reserve tank almost like something was opening and closing internally. Does this sound familiar to anyone out there and if so what was the true cause? faulty new thermastat?

2001 525i

Did you get a bosch waterpump? Please pm me if so.. I have a story to tell you

About 2 weeks ago replaced (car was running fine prior too)waterpump thermostat and housing, radiator and reserve tank(all parts purchased from pepboys minus reserve tank), bleed system test drove for about 20 minutes at night everything worked great. Next morning checked fluid level before taking off on the freeway(everything looked okay), about 5 minutes into the drive the temperature jumped to about 3/4 pulled car over right away opened vents to release preasure from system, opened radiator cap after system cooled a bit then started car and proceeded to add water back into the reserve tank while bleeder valves were opened, noticed once the water level was to level and the temp was at running temperature the water appeared to rise and fall (about 2 inches)within the reserve tank almost like something was opening and closing internally. Does this sound familiar to anyone out there and if so what was the true cause? faulty new thermastat?

2001 525i

I would hate to tell you this but you might need a new head gasket. Drain your oil and let it sit for a night and see if it has coolant in it. It seems like 6 cylinders like to do this a lot. I would do that ASAP because you could completely destroy the engine if you keep driving it

i bleed my coolant by having the defroster on/car off, fan on low, heat on max, and repeatedly squeezing the upper radiator hose while adding fluid keeping level at the top until i can't get any more air burped out. if you don't squeeze the hose you won't get all the air out. also make sure to start the car up and rev it a couple times before it warms up with the defroster on to force the coolant through the heater core.

well I re-bleed the system let car run at 2k rpms, ran fine for about 5 minutes just sitting at normal temp, no movement of the thermo gauge then just out of the blue the temp starts to rise and over heating occures, I think it has something to do with the new thermo stat I installed, why would it run fine at times then all of a sudden the temp starts to jump, makes no sense other than the thermo stat assembly failing. and to reply about the brand water pump, yes it is a bosch water pump, stant thermo. ran car the other day on the freeway for about 8 to 10 miles worked fine then out of the blue over heating occured. can't really think it's a bleeding issue still. getting ready to take to a mech. to deal with unless I decide to replace the stat with the old one to see if the problem goes away but what a pain.

well I re-bleed the system let car run at 2k rpms, ran fine for about 5 minutes just sitting at normal temp, no movement of the thermo gauge then just out of the blue the temp starts to rise and over heating occures, I think it has something to do with the new thermo stat I installed, why would it run fine at times then all of a sudden the temp starts to jump, makes no sense other than the thermo stat assembly failing. and to reply about the brand water pump, yes it is a bosch water pump, stant thermo. ran car the other day on the freeway for about 8 to 10 miles worked fine then out of the blue over heating occured. can't really think it's a bleeding issue still. getting ready to take to a mech. to deal with unless I decide to replace the stat with the old one to see if the problem goes away but what a pain.

Fan Clutch? If you were on the freeway you wouldnt need the fan running but if your car is sitting idling it would overheat. To test that start your car then after it gets up to temperature take a water bottle and see if you can stop the fan moving if so theres your problem

If so, these links were designed to help those with dire head gasket issues:

- Summary advice to provide users who suspect a major engine repair due to overheating (1) (2) (3) (4) & how to test an engine for a blown head gasket, cracked heads, a warped block, stripped head bolt threads, cam seizures, contaminated bearings, coolant hydrolock, or piston, ring, or valve damage (1) (2) & what are the major factors in deciding whether to rebuild the engine, replace the engine, or sell the car (1) & a DIY for replacing the I6 M54 head gasket (1) (2) & replacing the V8 M62TU head gasket (1) & why these engines are so prone to heat-related damage in the first place (1) & welding the crack between cylinder #3 and the water jacket on the exhaust side (1) & what engine swaps are most recommended (1) (2) (3) & where to obtain a new or rebuilt head (1) replacement short block or long block (1) (2) & how to lift & remove the engine (1) & the most recent real-world results from the last 50 people faced with similar blown engine problems from which this advice came from (1) (2) (3) (4) (5) (6) (7) (8) (9) (10) (11) (12) (13) (14) (15) (16) (17) (18) (19) (20) (21) (22) (23) (24) (25) (26) (27) (28) (29) (30) (31) (32) (33) (34) (35) (36) (37) (38) (39) (40) (41) (42) (43) (44) (45) (46) (47) (48) (49) (50)

As for simple bleeding, typing /bleed F3 in the bestlinks nets this PDF:

Please read the suggested threads, where the best always add value to those threads, either by pictures or by descriptions, so the next person with the same problem stands on your shoulders.
See also: E39 Bestlinks & How to easily find what you need

well I re-bleed the system let car run at 2k rpms, ran fine for about 5 minutes just sitting at normal temp, no movement of the thermo gauge then just out of the blue the temp starts to rise and over heating occures, I think it has something to do with the new thermo stat I installed, why would it run fine at times then all of a sudden the temp starts to jump, makes no sense other than the thermo stat assembly failing. and to reply about the brand water pump, yes it is a bosch water pump, stant thermo. ran car the other day on the freeway for about 8 to 10 miles worked fine then out of the blue over heating occured. can't really think it's a bleeding issue still. getting ready to take to a mech. to deal with unless I decide to replace the stat with the old one to see if the problem goes away but what a pain.

you might be bleeding it but that doesn't mean you got all the air out. try squeezing that upper radiator hose when the car is cold with the defroster on/heat high/fan low. i guarantee you will get air out

Is the Bosch water pump impeller plastic? If so take a few min of your time and remove it and inspect it. I do the same thing you did and purchased a water pump and Tstat from pep boys. The pump self destructed in less than 100 miles and I almost overheated. I sent it back to Bosch and they paid for the repairs to my vehicle because it was a defective part. I can't get into many details because I signed a document not to disclose much info. Take it out and report back

Is the Bosch water pump impeller plastic? If so take a few min of your time and remove it and inspect it. I do the same thing you did and purchased a water pump and Tstat from pep boys. The pump self destructed in less than 100 miles and I almost overheated. I sent it back to Bosch and they paid for the repairs to my vehicle because it was a defective part. I can't get into many details because I signed a document not to disclose much info. Take it out and report back

This is a rare post, diagnostically speaking, which covers the LOGIC of how to answer the OP's question.

Kudos to you!

To the OP:
Heed hh3uunp's words, for therein lies the secret!
a) Either air isn't moving ...
b) Or water isn't moving ...
c) Or air has replaced water.

__________________

Please read the suggested threads, where the best always add value to those threads, either by pictures or by descriptions, so the next person with the same problem stands on your shoulders.
See also: E39 Bestlinks & How to easily find what you need

Same here CN90--OP--you bought your cooling system from Pep Boys--that might be the problem--on the plastic impellor--that's been an on going problem for years--but too have one fall apart in short order like that--it's plain scary is what it is. I would suggest that you remove that water pump pronto --know it's a damn pain--but for the life of your engine--ya need to be sure

Re Water Pump, I love HEPU (learned it from the Volvo forum).
The HEPU WP (metal impeller) is now 6 years old in my car, zero problems.

I had the metal impeller in mine and it still failed, the bearing went and took the fan with it. We pulled it out and it looked like someone removed the impeller from the assembly with a can opener. Not the best morning haha

Typing /waterpump F3 in the bestlinks nets me:
- What brand of waterpump to buy (1)

__________________

Please read the suggested threads, where the best always add value to those threads, either by pictures or by descriptions, so the next person with the same problem stands on your shoulders.
See also: E39 Bestlinks & How to easily find what you need

well gang I think I found the problem thanks to your advise. Ran motor until up to running temp along the way used a heavy rag (not advisable ) to see if I could stop the belt driven cooling fan without much effort and sure enough it did stop. on my way to the shop to purchase a new fan clutch and will update with results once done. I would like to thank all for your helpful input and wish all the best.